Researchers studied how cannabidiol (CBD), a compound from cannabis used to treat seizures, affects liver cells in the laboratory. They discovered that CBD and some of its breakdown products can harm liver cells by disrupting the cell’s energy-producing structures (mitochondria) and triggering a self-cleaning process called autophagy that goes too far. While CBD is an FDA-approved medicine for certain types of childhood epilepsy, this research helps explain why liver damage is listed as a potential side effect. The findings suggest that understanding these harmful mechanisms could help doctors better monitor patients taking CBD and potentially develop safer versions of the drug.

The Quick Take

  • What they studied: How CBD and its breakdown products damage liver cells and what specific cellular processes cause this damage
  • Who participated: Laboratory experiments using human liver cells (HepG2 cells) grown in dishes—not human subjects or animals
  • Key finding: CBD damages liver cells primarily by breaking down the cell’s power plants (mitochondria) and triggering excessive autophagy, a self-cleaning process that becomes harmful when overactive
  • What it means for you: If you take CBD products, especially prescription CBD (Epidiolex) for seizures, your doctor should monitor your liver health through blood tests. This research doesn’t mean CBD is unsafe for everyone, but it explains why liver monitoring is important and suggests some people may be at higher risk than others

The Research Details

Scientists used laboratory-grown human liver cells to test how CBD and its breakdown products affect cell health. They exposed the cells to different amounts of CBD and measured what happened using advanced genetic testing (mRNA-sequencing) to see which genes turned on or off. They also directly measured how well the cell’s power plants (mitochondria) were working by testing specific energy-producing structures called respiratory complexes. Additionally, they used special dyes and imaging to watch for signs of cellular damage, including loss of energy and activation of the cell’s self-destruction cleanup process (autophagy).

This research approach is important because it helps identify the exact mechanisms—the ‘how’ and ‘why’—behind CBD’s harmful effects on liver cells. By understanding these specific pathways, researchers can better predict which patients might be at risk, develop monitoring strategies, and potentially create safer alternatives. Laboratory studies like this are a crucial first step before human testing and help explain why certain side effects appear on drug labels.

This study was published in Archives of Toxicology, a respected scientific journal focused on poison and drug safety research. The researchers used multiple complementary testing methods (genetic analysis, direct enzyme measurements, and visual confirmation) to verify their findings, which strengthens confidence in the results. However, because this is laboratory research using cells in dishes rather than whole organisms or humans, the findings need confirmation in additional studies before drawing final conclusions about real-world risk

What the Results Show

The research identified autophagy—a cellular self-cleaning process—as the main mechanism by which CBD damages liver cells. When autophagy becomes overactive, cells essentially eat themselves to death. Additionally, CBD strongly interfered with two critical energy-producing structures in cells (Complexes IV and V) and moderately affected two others (Complexes II and III), essentially breaking the cell’s power generation system. This energy loss was confirmed by multiple tests showing that cells exposed to CBD lost their ability to produce and maintain energy. The researchers also found that the cell’s energy-storing structures (mitochondria) became dysfunctional, losing their protective membrane potential—like a battery losing its charge.

The study examined two breakdown products of CBD that the body creates after consuming it. The first breakdown product (7-hydroxy-CBD) behaved similarly to CBD itself, causing strong damage to energy-producing structures and triggering excessive autophagy. The second breakdown product (7-carboxy-CBD) triggered autophagy but caused less damage to the energy-producing structures. This suggests that different forms of CBD and its breakdown products may pose different levels of risk to liver cells, which could be important for understanding individual differences in how people respond to CBD treatment.

This research builds on the scientists’ earlier work showing that CBD harms liver cells. The new study goes deeper by identifying the specific cellular mechanisms involved. Previous research had noted that CBD causes cell cycle problems and cell death, but this study pinpoints exactly how that happens—through mitochondrial damage and excessive autophagy. These findings align with other research showing that many drugs can damage liver cells through similar mitochondrial mechanisms, suggesting this is a common pathway for drug-related liver injury.

This study used liver cells grown in laboratory dishes, which don’t perfectly replicate how a whole liver works in a living person. The cells were exposed to CBD in controlled amounts that may differ from real-world exposure in patients. The research doesn’t tell us how common or severe these effects are in actual patients taking CBD, or whether some people are more susceptible than others. Additionally, the study doesn’t examine how the body’s natural defenses or other factors might protect against these harmful effects. Finally, because this is laboratory research, we cannot directly conclude that these cellular effects will cause noticeable liver damage in all people taking CBD

The Bottom Line

If you are taking prescription CBD (Epidiolex) for seizures, continue taking it as prescribed by your doctor—the benefits for seizure control are well-established and important. However, ask your doctor about liver function monitoring through blood tests (checking liver enzymes), especially when starting treatment or increasing doses. For non-prescription CBD products, be aware that liver safety data is more limited, and discuss use with your healthcare provider, particularly if you have existing liver problems or take other medications. The evidence suggests caution rather than avoidance, with appropriate medical supervision.

This research is most relevant for people taking prescription CBD (Epidiolex) for childhood epilepsy and their families, as well as patients considering CBD for other conditions. People with existing liver disease or those taking multiple medications that affect the liver should be especially cautious and discuss CBD use with their doctor. Healthcare providers should use this information to justify liver monitoring in CBD patients. People using non-prescription CBD products should be aware of potential risks, though the actual risk level in real patients remains unclear. This research is less immediately relevant for people not taking CBD products.

Liver damage from medications typically develops over weeks to months of regular use, not immediately. If you’re taking CBD, liver enzyme changes might appear within the first few weeks to months of treatment, which is why initial monitoring is important. However, not everyone who takes CBD will experience liver damage—some people may tolerate it well. Long-term effects and individual risk factors are still being studied, so ongoing monitoring throughout treatment is recommended rather than expecting problems at a specific timepoint

Want to Apply This Research?

  • If taking CBD, track monthly liver function test results (AST and ALT enzyme levels) in the app, noting the date, values, and any symptoms like fatigue, yellowing of skin/eyes, or abdominal discomfort. Set reminders for scheduled doctor appointments for liver monitoring
  • Use the app to log daily CBD dose and timing, any side effects noticed, and medication interactions. Create a checklist for pre-appointment questions about liver safety and monitoring frequency. Set alerts to remind you to schedule liver function tests at intervals recommended by your doctor
  • Establish a baseline liver function test before starting CBD, then track results at regular intervals (typically every 3-6 months initially, then annually if stable). Use the app to create a trend chart showing liver enzyme levels over time, making it easy to spot concerning changes. Document any new symptoms and share this data with your healthcare provider at each visit

This research describes laboratory findings in isolated liver cells and does not directly prove that CBD causes liver damage in all people who take it. While CBD is FDA-approved for certain seizure disorders, liver toxicity is a known potential side effect. This article is for educational purposes only and should not replace medical advice. If you are taking CBD or considering it, consult with your healthcare provider about appropriate monitoring and whether it is right for you. Do not stop taking prescribed CBD without medical guidance. People with existing liver disease should discuss CBD use with their doctor before starting treatment. This research does not establish safe or unsafe dosage levels for humans.